Added check rules for district ID consistency and rights

[antoineludeau]

Context

For reinforcing BAL controls, id-fix is making some checks when receiving a BAL

Enhancement

This PR adds checking rules on district ID :

• Only 1 district ID in the received BAL. As a consequence, we ensure 1 BAL = 1 district ID = 1 cog
• the district ID used in the BAL is the same as the district ID we have in our data base (so that we ensure that the district has the right to updates the addresses and toponyms linked to this district ID).